Field of the Invention
The present invention relates to a laser device, and more specifically relates to a laser device comprising an electrically conductive member that connects laser diode modules.
Related Art
When using an excitation laser diode module for fiber laser, a plurality of laser diode modules need to be electrically connected, in order to fulfill a predetermined output. As a typical method for such connection, an electrically conductive member (sheet metal) is soldered between electrodes of the excitation laser diode modules. During soldering, a soldering iron needs to be strongly pressed against the sheet metal, in order to sufficiently heat the sheet metal. In particular, lead-free solder having a high melting point is poor in workability, requires heat applied for a long time, and may therefore involve a risk of heating and damaging the excitation laser diode modules in some cases. In order to avoid such damage, the soldering needs to be completed within several tens of seconds.
In general, excitation laser diode modules are arranged on a heat dissipation sheet; however, if accuracy in position is not secured in this arrangement, it will fundamentally be difficult to attach the electrically conductive member for connecting the excitation laser diode modules. Further, even if the electrically conductive member could be attached, the required accuracy in attachment position cannot be secured. In this manner, if the required accuracy in attachment position of the electrically conductive member cannot be secured, a distance between the electrically conductive member and the excitation laser diode modules (main body thereof), or a distance between the excitation laser diode module and the optical fiber, cannot be secured. This may alternatively cause another problem in which an insulation distance between the electrically conductive member and the cooling plate cannot be secured. Therefore, a fastening jig has conventionally been used for preventing a sheet metal from tilting or deviating in position when pressing a soldering iron against a sheet metal, in a soldering operation of an electrically conductive member. However, such a jig requires operation time for attachment and detachment, which has been an obstacle to improving the working efficiency in a soldering operation.
Note that various technologies for connecting devices through an electrically conductive member have heretofore been proposed. One of such examples is a technological proposal, in which a battery pack is configured by connecting a plurality of battery cells through an electrically conductive member (bus bar) (for example, refer to Patent Document 1). According to the technology disclosed in Patent Document 1, an electrically conductive member is provided with through holes having a diameter slightly smaller than a diameter of terminals of battery cells, and the through holes are provided with slits in a radial direction. By providing such slits, the through holes are elastically deformed to allow the terminals of the battery cells to be inserted therethrough. Since the electrically conductive member can firmly hold the terminals of the battery cells, the number of processes for terminal connection can be reduced, as compared to conventional connection by fixation with nuts or bolts, according to Patent Document 1.
Further, there has been a proposal of a power supply as well, in which a plurality of battery cells are stacked, and the power supply includes an electrically conductive member (bus bar) for electrically connecting adjacent battery cells through output terminals of the battery cells (for example, refer to Patent Document 2). According to the technology disclosed in Patent Document 2, the output terminals of the battery cells are elastically deformable, and the output terminals are elastically deformed and firmly inserted into connection holes in the electrically conductive member. As a result, positional deviation of the output terminals of the battery cells in relation to the electrically conductive member (bus bar) can be absorbed, and the reliability of connection between the battery cells can be improved, according to Patent Document 2.
Further, there has been a technological proposal of relaxing a stress due to deformation of an electrode terminal member, in which the electrode terminal member is extended from an electrode fixation portion of a transformer, and a tip side thereof is connected to an electronic substrate (for example, refer to Patent Document 3). According to the technology disclosed in Patent Document 3, when a large electric current is applied to the electrode terminal member which is an electrically conductive member, the electrode terminal member generates heat, expands, and creates a stress; and the stress is relaxed by way of a spring action of a member referred to as an absorption protrusion engaged with the electrode terminal member, whereby the stress applied to a soldering portion is suppressed.
Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2011-233491
Patent Document 2: Japanese Unexamined Patent Application, Publication No. 2013-26191
Patent Document 3: Japanese Unexamined Patent Application, Publication No. 2007-220491